linux/net/decnet/dn_table.c
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   1/*
   2 * DECnet       An implementation of the DECnet protocol suite for the LINUX
   3 *              operating system.  DECnet is implemented using the  BSD Socket
   4 *              interface as the means of communication with the user level.
   5 *
   6 *              DECnet Routing Forwarding Information Base (Routing Tables)
   7 *
   8 * Author:      Steve Whitehouse <SteveW@ACM.org>
   9 *              Mostly copied from the IPv4 routing code
  10 *
  11 *
  12 * Changes:
  13 *
  14 */
  15#include <linux/string.h>
  16#include <linux/net.h>
  17#include <linux/socket.h>
  18#include <linux/slab.h>
  19#include <linux/sockios.h>
  20#include <linux/init.h>
  21#include <linux/skbuff.h>
  22#include <linux/netlink.h>
  23#include <linux/rtnetlink.h>
  24#include <linux/proc_fs.h>
  25#include <linux/netdevice.h>
  26#include <linux/timer.h>
  27#include <linux/spinlock.h>
  28#include <linux/atomic.h>
  29#include <asm/uaccess.h>
  30#include <linux/route.h> /* RTF_xxx */
  31#include <net/neighbour.h>
  32#include <net/netlink.h>
  33#include <net/dst.h>
  34#include <net/flow.h>
  35#include <net/fib_rules.h>
  36#include <net/dn.h>
  37#include <net/dn_route.h>
  38#include <net/dn_fib.h>
  39#include <net/dn_neigh.h>
  40#include <net/dn_dev.h>
  41
  42struct dn_zone
  43{
  44        struct dn_zone          *dz_next;
  45        struct dn_fib_node      **dz_hash;
  46        int                     dz_nent;
  47        int                     dz_divisor;
  48        u32                     dz_hashmask;
  49#define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  50        int                     dz_order;
  51        __le16                  dz_mask;
  52#define DZ_MASK(dz)     ((dz)->dz_mask)
  53};
  54
  55struct dn_hash
  56{
  57        struct dn_zone  *dh_zones[17];
  58        struct dn_zone  *dh_zone_list;
  59};
  60
  61#define dz_key_0(key)           ((key).datum = 0)
  62
  63#define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  64        for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  65
  66#define endfor_nexthops(fi) }
  67
  68#define DN_MAX_DIVISOR 1024
  69#define DN_S_ZOMBIE 1
  70#define DN_S_ACCESSED 2
  71
  72#define DN_FIB_SCAN(f, fp) \
  73for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  74
  75#define DN_FIB_SCAN_KEY(f, fp, key) \
  76for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  77
  78#define RT_TABLE_MIN 1
  79#define DN_FIB_TABLE_HASHSZ 256
  80static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  81static DEFINE_RWLOCK(dn_fib_tables_lock);
  82
  83static struct kmem_cache *dn_hash_kmem __read_mostly;
  84static int dn_fib_hash_zombies;
  85
  86static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  87{
  88        u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
  89        h ^= (h >> 10);
  90        h ^= (h >> 6);
  91        h &= DZ_HASHMASK(dz);
  92        return *(dn_fib_idx_t *)&h;
  93}
  94
  95static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  96{
  97        dn_fib_key_t k;
  98        k.datum = dst & DZ_MASK(dz);
  99        return k;
 100}
 101
 102static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 103{
 104        return &dz->dz_hash[dn_hash(key, dz).datum];
 105}
 106
 107static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 108{
 109        return dz->dz_hash[dn_hash(key, dz).datum];
 110}
 111
 112static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 113{
 114        return a.datum == b.datum;
 115}
 116
 117static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 118{
 119        return a.datum <= b.datum;
 120}
 121
 122static inline void dn_rebuild_zone(struct dn_zone *dz,
 123                                   struct dn_fib_node **old_ht,
 124                                   int old_divisor)
 125{
 126        struct dn_fib_node *f, **fp, *next;
 127        int i;
 128
 129        for(i = 0; i < old_divisor; i++) {
 130                for(f = old_ht[i]; f; f = next) {
 131                        next = f->fn_next;
 132                        for(fp = dn_chain_p(f->fn_key, dz);
 133                                *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 134                                fp = &(*fp)->fn_next)
 135                                /* NOTHING */;
 136                        f->fn_next = *fp;
 137                        *fp = f;
 138                }
 139        }
 140}
 141
 142static void dn_rehash_zone(struct dn_zone *dz)
 143{
 144        struct dn_fib_node **ht, **old_ht;
 145        int old_divisor, new_divisor;
 146        u32 new_hashmask;
 147
 148        old_divisor = dz->dz_divisor;
 149
 150        switch (old_divisor) {
 151        case 16:
 152                new_divisor = 256;
 153                new_hashmask = 0xFF;
 154                break;
 155        default:
 156                printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
 157                       old_divisor);
 158        case 256:
 159                new_divisor = 1024;
 160                new_hashmask = 0x3FF;
 161                break;
 162        }
 163
 164        ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 165        if (ht == NULL)
 166                return;
 167
 168        write_lock_bh(&dn_fib_tables_lock);
 169        old_ht = dz->dz_hash;
 170        dz->dz_hash = ht;
 171        dz->dz_hashmask = new_hashmask;
 172        dz->dz_divisor = new_divisor;
 173        dn_rebuild_zone(dz, old_ht, old_divisor);
 174        write_unlock_bh(&dn_fib_tables_lock);
 175        kfree(old_ht);
 176}
 177
 178static void dn_free_node(struct dn_fib_node *f)
 179{
 180        dn_fib_release_info(DN_FIB_INFO(f));
 181        kmem_cache_free(dn_hash_kmem, f);
 182}
 183
 184
 185static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 186{
 187        int i;
 188        struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 189        if (!dz)
 190                return NULL;
 191
 192        if (z) {
 193                dz->dz_divisor = 16;
 194                dz->dz_hashmask = 0x0F;
 195        } else {
 196                dz->dz_divisor = 1;
 197                dz->dz_hashmask = 0;
 198        }
 199
 200        dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 201        if (!dz->dz_hash) {
 202                kfree(dz);
 203                return NULL;
 204        }
 205
 206        dz->dz_order = z;
 207        dz->dz_mask = dnet_make_mask(z);
 208
 209        for(i = z + 1; i <= 16; i++)
 210                if (table->dh_zones[i])
 211                        break;
 212
 213        write_lock_bh(&dn_fib_tables_lock);
 214        if (i>16) {
 215                dz->dz_next = table->dh_zone_list;
 216                table->dh_zone_list = dz;
 217        } else {
 218                dz->dz_next = table->dh_zones[i]->dz_next;
 219                table->dh_zones[i]->dz_next = dz;
 220        }
 221        table->dh_zones[z] = dz;
 222        write_unlock_bh(&dn_fib_tables_lock);
 223        return dz;
 224}
 225
 226
 227static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 228{
 229        struct rtnexthop *nhp;
 230        int nhlen;
 231
 232        if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 233                return 1;
 234
 235        if (rta->rta_oif || rta->rta_gw) {
 236                if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 237                    (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 238                        return 0;
 239                return 1;
 240        }
 241
 242        if (rta->rta_mp == NULL)
 243                return 0;
 244
 245        nhp = RTA_DATA(rta->rta_mp);
 246        nhlen = RTA_PAYLOAD(rta->rta_mp);
 247
 248        for_nexthops(fi) {
 249                int attrlen = nhlen - sizeof(struct rtnexthop);
 250                __le16 gw;
 251
 252                if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 253                        return -EINVAL;
 254                if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 255                        return 1;
 256                if (attrlen) {
 257                        gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 258
 259                        if (gw && gw != nh->nh_gw)
 260                                return 1;
 261                }
 262                nhp = RTNH_NEXT(nhp);
 263        } endfor_nexthops(fi);
 264
 265        return 0;
 266}
 267
 268static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 269{
 270        size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 271                         + nla_total_size(4) /* RTA_TABLE */
 272                         + nla_total_size(2) /* RTA_DST */
 273                         + nla_total_size(4); /* RTA_PRIORITY */
 274
 275        /* space for nested metrics */
 276        payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 277
 278        if (fi->fib_nhs) {
 279                /* Also handles the special case fib_nhs == 1 */
 280
 281                /* each nexthop is packed in an attribute */
 282                size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 283
 284                /* may contain a gateway attribute */
 285                nhsize += nla_total_size(4);
 286
 287                /* all nexthops are packed in a nested attribute */
 288                payload += nla_total_size(fi->fib_nhs * nhsize);
 289        }
 290
 291        return payload;
 292}
 293
 294static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 295                        u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 296                        struct dn_fib_info *fi, unsigned int flags)
 297{
 298        struct rtmsg *rtm;
 299        struct nlmsghdr *nlh;
 300
 301        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 302        if (!nlh)
 303                return -EMSGSIZE;
 304
 305        rtm = nlmsg_data(nlh);
 306        rtm->rtm_family = AF_DECnet;
 307        rtm->rtm_dst_len = dst_len;
 308        rtm->rtm_src_len = 0;
 309        rtm->rtm_tos = 0;
 310        rtm->rtm_table = tb_id;
 311        rtm->rtm_flags = fi->fib_flags;
 312        rtm->rtm_scope = scope;
 313        rtm->rtm_type  = type;
 314        rtm->rtm_protocol = fi->fib_protocol;
 315
 316        if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 317                goto errout;
 318
 319        if (rtm->rtm_dst_len &&
 320            nla_put(skb, RTA_DST, 2, dst) < 0)
 321                goto errout;
 322
 323        if (fi->fib_priority &&
 324            nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 325                goto errout;
 326
 327        if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 328                goto errout;
 329
 330        if (fi->fib_nhs == 1) {
 331                if (fi->fib_nh->nh_gw &&
 332                    nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 333                        goto errout;
 334
 335                if (fi->fib_nh->nh_oif &&
 336                    nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 337                        goto errout;
 338        }
 339
 340        if (fi->fib_nhs > 1) {
 341                struct rtnexthop *nhp;
 342                struct nlattr *mp_head;
 343
 344                if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 345                        goto errout;
 346
 347                for_nexthops(fi) {
 348                        if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 349                                goto errout;
 350
 351                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
 352                        nhp->rtnh_hops = nh->nh_weight - 1;
 353                        nhp->rtnh_ifindex = nh->nh_oif;
 354
 355                        if (nh->nh_gw &&
 356                            nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 357                                goto errout;
 358
 359                        nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 360                } endfor_nexthops(fi);
 361
 362                nla_nest_end(skb, mp_head);
 363        }
 364
 365        return nlmsg_end(skb, nlh);
 366
 367errout:
 368        nlmsg_cancel(skb, nlh);
 369        return -EMSGSIZE;
 370}
 371
 372
 373static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 374                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 375{
 376        struct sk_buff *skb;
 377        u32 portid = req ? req->portid : 0;
 378        int err = -ENOBUFS;
 379
 380        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 381        if (skb == NULL)
 382                goto errout;
 383
 384        err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 385                               f->fn_type, f->fn_scope, &f->fn_key, z,
 386                               DN_FIB_INFO(f), 0);
 387        if (err < 0) {
 388                /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 389                WARN_ON(err == -EMSGSIZE);
 390                kfree_skb(skb);
 391                goto errout;
 392        }
 393        rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 394        return;
 395errout:
 396        if (err < 0)
 397                rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 398}
 399
 400static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 401                                struct netlink_callback *cb,
 402                                struct dn_fib_table *tb,
 403                                struct dn_zone *dz,
 404                                struct dn_fib_node *f)
 405{
 406        int i, s_i;
 407
 408        s_i = cb->args[4];
 409        for(i = 0; f; i++, f = f->fn_next) {
 410                if (i < s_i)
 411                        continue;
 412                if (f->fn_state & DN_S_ZOMBIE)
 413                        continue;
 414                if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 415                                cb->nlh->nlmsg_seq,
 416                                RTM_NEWROUTE,
 417                                tb->n,
 418                                (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 419                                f->fn_scope, &f->fn_key, dz->dz_order,
 420                                f->fn_info, NLM_F_MULTI) < 0) {
 421                        cb->args[4] = i;
 422                        return -1;
 423                }
 424        }
 425        cb->args[4] = i;
 426        return skb->len;
 427}
 428
 429static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 430                                struct netlink_callback *cb,
 431                                struct dn_fib_table *tb,
 432                                struct dn_zone *dz)
 433{
 434        int h, s_h;
 435
 436        s_h = cb->args[3];
 437        for(h = 0; h < dz->dz_divisor; h++) {
 438                if (h < s_h)
 439                        continue;
 440                if (h > s_h)
 441                        memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 442                if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 443                        continue;
 444                if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 445                        cb->args[3] = h;
 446                        return -1;
 447                }
 448        }
 449        cb->args[3] = h;
 450        return skb->len;
 451}
 452
 453static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 454                                struct netlink_callback *cb)
 455{
 456        int m, s_m;
 457        struct dn_zone *dz;
 458        struct dn_hash *table = (struct dn_hash *)tb->data;
 459
 460        s_m = cb->args[2];
 461        read_lock(&dn_fib_tables_lock);
 462        for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 463                if (m < s_m)
 464                        continue;
 465                if (m > s_m)
 466                        memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 467
 468                if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 469                        cb->args[2] = m;
 470                        read_unlock(&dn_fib_tables_lock);
 471                        return -1;
 472                }
 473        }
 474        read_unlock(&dn_fib_tables_lock);
 475        cb->args[2] = m;
 476
 477        return skb->len;
 478}
 479
 480int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 481{
 482        struct net *net = sock_net(skb->sk);
 483        unsigned int h, s_h;
 484        unsigned int e = 0, s_e;
 485        struct dn_fib_table *tb;
 486        struct hlist_node *node;
 487        int dumped = 0;
 488
 489        if (!net_eq(net, &init_net))
 490                return 0;
 491
 492        if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 493                ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 494                        return dn_cache_dump(skb, cb);
 495
 496        s_h = cb->args[0];
 497        s_e = cb->args[1];
 498
 499        for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 500                e = 0;
 501                hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 502                        if (e < s_e)
 503                                goto next;
 504                        if (dumped)
 505                                memset(&cb->args[2], 0, sizeof(cb->args) -
 506                                                 2 * sizeof(cb->args[0]));
 507                        if (tb->dump(tb, skb, cb) < 0)
 508                                goto out;
 509                        dumped = 1;
 510next:
 511                        e++;
 512                }
 513        }
 514out:
 515        cb->args[1] = e;
 516        cb->args[0] = h;
 517
 518        return skb->len;
 519}
 520
 521static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
 522{
 523        struct dn_hash *table = (struct dn_hash *)tb->data;
 524        struct dn_fib_node *new_f, *f, **fp, **del_fp;
 525        struct dn_zone *dz;
 526        struct dn_fib_info *fi;
 527        int z = r->rtm_dst_len;
 528        int type = r->rtm_type;
 529        dn_fib_key_t key;
 530        int err;
 531
 532        if (z > 16)
 533                return -EINVAL;
 534
 535        dz = table->dh_zones[z];
 536        if (!dz && !(dz = dn_new_zone(table, z)))
 537                return -ENOBUFS;
 538
 539        dz_key_0(key);
 540        if (rta->rta_dst) {
 541                __le16 dst;
 542                memcpy(&dst, rta->rta_dst, 2);
 543                if (dst & ~DZ_MASK(dz))
 544                        return -EINVAL;
 545                key = dz_key(dst, dz);
 546        }
 547
 548        if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 549                return err;
 550
 551        if (dz->dz_nent > (dz->dz_divisor << 2) &&
 552                        dz->dz_divisor > DN_MAX_DIVISOR &&
 553                        (z==16 || (1<<z) > dz->dz_divisor))
 554                dn_rehash_zone(dz);
 555
 556        fp = dn_chain_p(key, dz);
 557
 558        DN_FIB_SCAN(f, fp) {
 559                if (dn_key_leq(key, f->fn_key))
 560                        break;
 561        }
 562
 563        del_fp = NULL;
 564
 565        if (f && (f->fn_state & DN_S_ZOMBIE) &&
 566                        dn_key_eq(f->fn_key, key)) {
 567                del_fp = fp;
 568                fp = &f->fn_next;
 569                f = *fp;
 570                goto create;
 571        }
 572
 573        DN_FIB_SCAN_KEY(f, fp, key) {
 574                if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 575                        break;
 576        }
 577
 578        if (f && dn_key_eq(f->fn_key, key) &&
 579                        fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 580                struct dn_fib_node **ins_fp;
 581
 582                err = -EEXIST;
 583                if (n->nlmsg_flags & NLM_F_EXCL)
 584                        goto out;
 585
 586                if (n->nlmsg_flags & NLM_F_REPLACE) {
 587                        del_fp = fp;
 588                        fp = &f->fn_next;
 589                        f = *fp;
 590                        goto replace;
 591                }
 592
 593                ins_fp = fp;
 594                err = -EEXIST;
 595
 596                DN_FIB_SCAN_KEY(f, fp, key) {
 597                        if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 598                                break;
 599                        if (f->fn_type == type &&
 600                            f->fn_scope == r->rtm_scope &&
 601                            DN_FIB_INFO(f) == fi)
 602                                goto out;
 603                }
 604
 605                if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 606                        fp = ins_fp;
 607                        f = *fp;
 608                }
 609        }
 610
 611create:
 612        err = -ENOENT;
 613        if (!(n->nlmsg_flags & NLM_F_CREATE))
 614                goto out;
 615
 616replace:
 617        err = -ENOBUFS;
 618        new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 619        if (new_f == NULL)
 620                goto out;
 621
 622        new_f->fn_key = key;
 623        new_f->fn_type = type;
 624        new_f->fn_scope = r->rtm_scope;
 625        DN_FIB_INFO(new_f) = fi;
 626
 627        new_f->fn_next = f;
 628        write_lock_bh(&dn_fib_tables_lock);
 629        *fp = new_f;
 630        write_unlock_bh(&dn_fib_tables_lock);
 631        dz->dz_nent++;
 632
 633        if (del_fp) {
 634                f = *del_fp;
 635                write_lock_bh(&dn_fib_tables_lock);
 636                *del_fp = f->fn_next;
 637                write_unlock_bh(&dn_fib_tables_lock);
 638
 639                if (!(f->fn_state & DN_S_ZOMBIE))
 640                        dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 641                if (f->fn_state & DN_S_ACCESSED)
 642                        dn_rt_cache_flush(-1);
 643                dn_free_node(f);
 644                dz->dz_nent--;
 645        } else {
 646                dn_rt_cache_flush(-1);
 647        }
 648
 649        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 650
 651        return 0;
 652out:
 653        dn_fib_release_info(fi);
 654        return err;
 655}
 656
 657
 658static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
 659{
 660        struct dn_hash *table = (struct dn_hash*)tb->data;
 661        struct dn_fib_node **fp, **del_fp, *f;
 662        int z = r->rtm_dst_len;
 663        struct dn_zone *dz;
 664        dn_fib_key_t key;
 665        int matched;
 666
 667
 668        if (z > 16)
 669                return -EINVAL;
 670
 671        if ((dz = table->dh_zones[z]) == NULL)
 672                return -ESRCH;
 673
 674        dz_key_0(key);
 675        if (rta->rta_dst) {
 676                __le16 dst;
 677                memcpy(&dst, rta->rta_dst, 2);
 678                if (dst & ~DZ_MASK(dz))
 679                        return -EINVAL;
 680                key = dz_key(dst, dz);
 681        }
 682
 683        fp = dn_chain_p(key, dz);
 684
 685        DN_FIB_SCAN(f, fp) {
 686                if (dn_key_eq(f->fn_key, key))
 687                        break;
 688                if (dn_key_leq(key, f->fn_key))
 689                        return -ESRCH;
 690        }
 691
 692        matched = 0;
 693        del_fp = NULL;
 694        DN_FIB_SCAN_KEY(f, fp, key) {
 695                struct dn_fib_info *fi = DN_FIB_INFO(f);
 696
 697                if (f->fn_state & DN_S_ZOMBIE)
 698                        return -ESRCH;
 699
 700                matched++;
 701
 702                if (del_fp == NULL &&
 703                                (!r->rtm_type || f->fn_type == r->rtm_type) &&
 704                                (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 705                                (!r->rtm_protocol ||
 706                                        fi->fib_protocol == r->rtm_protocol) &&
 707                                dn_fib_nh_match(r, n, rta, fi) == 0)
 708                        del_fp = fp;
 709        }
 710
 711        if (del_fp) {
 712                f = *del_fp;
 713                dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 714
 715                if (matched != 1) {
 716                        write_lock_bh(&dn_fib_tables_lock);
 717                        *del_fp = f->fn_next;
 718                        write_unlock_bh(&dn_fib_tables_lock);
 719
 720                        if (f->fn_state & DN_S_ACCESSED)
 721                                dn_rt_cache_flush(-1);
 722                        dn_free_node(f);
 723                        dz->dz_nent--;
 724                } else {
 725                        f->fn_state |= DN_S_ZOMBIE;
 726                        if (f->fn_state & DN_S_ACCESSED) {
 727                                f->fn_state &= ~DN_S_ACCESSED;
 728                                dn_rt_cache_flush(-1);
 729                        }
 730                        if (++dn_fib_hash_zombies > 128)
 731                                dn_fib_flush();
 732                }
 733
 734                return 0;
 735        }
 736
 737        return -ESRCH;
 738}
 739
 740static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 741{
 742        int found = 0;
 743        struct dn_fib_node *f;
 744
 745        while((f = *fp) != NULL) {
 746                struct dn_fib_info *fi = DN_FIB_INFO(f);
 747
 748                if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 749                        write_lock_bh(&dn_fib_tables_lock);
 750                        *fp = f->fn_next;
 751                        write_unlock_bh(&dn_fib_tables_lock);
 752
 753                        dn_free_node(f);
 754                        found++;
 755                        continue;
 756                }
 757                fp = &f->fn_next;
 758        }
 759
 760        return found;
 761}
 762
 763static int dn_fib_table_flush(struct dn_fib_table *tb)
 764{
 765        struct dn_hash *table = (struct dn_hash *)tb->data;
 766        struct dn_zone *dz;
 767        int found = 0;
 768
 769        dn_fib_hash_zombies = 0;
 770        for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 771                int i;
 772                int tmp = 0;
 773                for(i = dz->dz_divisor-1; i >= 0; i--)
 774                        tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 775                dz->dz_nent -= tmp;
 776                found += tmp;
 777        }
 778
 779        return found;
 780}
 781
 782static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 783{
 784        int err;
 785        struct dn_zone *dz;
 786        struct dn_hash *t = (struct dn_hash *)tb->data;
 787
 788        read_lock(&dn_fib_tables_lock);
 789        for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 790                struct dn_fib_node *f;
 791                dn_fib_key_t k = dz_key(flp->daddr, dz);
 792
 793                for(f = dz_chain(k, dz); f; f = f->fn_next) {
 794                        if (!dn_key_eq(k, f->fn_key)) {
 795                                if (dn_key_leq(k, f->fn_key))
 796                                        break;
 797                                else
 798                                        continue;
 799                        }
 800
 801                        f->fn_state |= DN_S_ACCESSED;
 802
 803                        if (f->fn_state&DN_S_ZOMBIE)
 804                                continue;
 805
 806                        if (f->fn_scope < flp->flowidn_scope)
 807                                continue;
 808
 809                        err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 810
 811                        if (err == 0) {
 812                                res->type = f->fn_type;
 813                                res->scope = f->fn_scope;
 814                                res->prefixlen = dz->dz_order;
 815                                goto out;
 816                        }
 817                        if (err < 0)
 818                                goto out;
 819                }
 820        }
 821        err = 1;
 822out:
 823        read_unlock(&dn_fib_tables_lock);
 824        return err;
 825}
 826
 827
 828struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 829{
 830        struct dn_fib_table *t;
 831        struct hlist_node *node;
 832        unsigned int h;
 833
 834        if (n < RT_TABLE_MIN)
 835                return NULL;
 836
 837        if (n > RT_TABLE_MAX)
 838                return NULL;
 839
 840        h = n & (DN_FIB_TABLE_HASHSZ - 1);
 841        rcu_read_lock();
 842        hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 843                if (t->n == n) {
 844                        rcu_read_unlock();
 845                        return t;
 846                }
 847        }
 848        rcu_read_unlock();
 849
 850        if (!create)
 851                return NULL;
 852
 853        if (in_interrupt()) {
 854                net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 855                return NULL;
 856        }
 857
 858        t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 859                    GFP_KERNEL);
 860        if (t == NULL)
 861                return NULL;
 862
 863        t->n = n;
 864        t->insert = dn_fib_table_insert;
 865        t->delete = dn_fib_table_delete;
 866        t->lookup = dn_fib_table_lookup;
 867        t->flush  = dn_fib_table_flush;
 868        t->dump = dn_fib_table_dump;
 869        hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 870
 871        return t;
 872}
 873
 874struct dn_fib_table *dn_fib_empty_table(void)
 875{
 876        u32 id;
 877
 878        for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 879                if (dn_fib_get_table(id, 0) == NULL)
 880                        return dn_fib_get_table(id, 1);
 881        return NULL;
 882}
 883
 884void dn_fib_flush(void)
 885{
 886        int flushed = 0;
 887        struct dn_fib_table *tb;
 888        struct hlist_node *node;
 889        unsigned int h;
 890
 891        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 892                hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 893                        flushed += tb->flush(tb);
 894        }
 895
 896        if (flushed)
 897                dn_rt_cache_flush(-1);
 898}
 899
 900void __init dn_fib_table_init(void)
 901{
 902        dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 903                                        sizeof(struct dn_fib_info),
 904                                        0, SLAB_HWCACHE_ALIGN,
 905                                        NULL);
 906}
 907
 908void __exit dn_fib_table_cleanup(void)
 909{
 910        struct dn_fib_table *t;
 911        struct hlist_node *node, *next;
 912        unsigned int h;
 913
 914        write_lock(&dn_fib_tables_lock);
 915        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 916                hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 917                                          hlist) {
 918                        hlist_del(&t->hlist);
 919                        kfree(t);
 920                }
 921        }
 922        write_unlock(&dn_fib_tables_lock);
 923}
 924
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